cfa_to_rgb — 2D `color` op

• Data kinds: image → color

• Call: fullseye.apply(img, "cfa_to_rgb", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: cfa_to_rgb (the HALCON reference is a useful guide to its meaning and parameters)

cfa_to_rgb: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):

▸ cfa_to_rgb: knob a sweep (docs site)

*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

▸ cfa_to_rgb: other inputs (docs site)

*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*

Usage

Demosaicing from a Bayer pattern (CFA: Color Filter Array) to an RGB image. Approximates HALCON's `cfa_to_rgb` (converts a single-chip color filter array image to an RGB image).

> The detailed description below is the original text — the summary and the headings are translated.

単一チャンネルのグレースケール画像を Bayer パターンの生データとみなし、

OpenCV の `cv2.cvtColor` でデモザイクして 3 チャンネル RGB に復元する。

image から color への橋渡し op（進化がカラー系統に入る唯一の入口）。

a は Bayer パターンの並び順を 4 通り（BG/GB/RG/GR の並び）から選ぶ

（`min(3, int(a * 4))` で 0〜3 に量子化）。b は未使用。

パターンが実際の入力と合わない場合、色ズレ・モアレが出る（本来の Bayer

配置が分からない合成画像に対してはどれも「それらしい」RGB化でしかない）。

Detailed usage guide

• gallery2d_color_artistic family guide

Background guides (the physics and conventions behind this op)

• colorimetry — 測色と分光の知識 — 色は「分光 × 光源 × 観測者」でしか決まらない

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

cfa_to_rgb 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_color_artistic — py -3.11 examples/gallery2d_color_artistic.py

Ops the type connects to (they accept `color` as input)

identity · trans_from_rgb · trans_to_rgb · linear_trans_color · principal_comp · rgb1_to_gray · rgb3_to_gray · access_channel

Same category (`color`)

trans_from_rgb · trans_to_rgb · linear_trans_color · principal_comp · rgb1_to_gray · rgb3_to_gray · access_channel

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

cfa_to_rgb — 2D color op